Extend readme

Dockerfile

@@ -1,4 +1,4 @@
-FROM ghcr.io/rverst/stargazer:v1.0.2
+FROM ghcr.io/rverst/stargazer:latest
 
 COPY entrypoint.sh /entrypoint.sh
 

README.md

@@ -1,11 +1,70 @@
 # stargazer
 
 *stargazer* creates a sorted list of your stared github repositories.
-Like an [![Awesome](https://awesome.re/badge.svg)](https://awesome.re) 
+Like an [![Awesome](https://awesome.re/badge.svg)](https://awesome.re)
 list, but personal.
 
+## Usage
+
+Probably the easiest way to get your own stargazer list is to have a
+repository with a workflow that uses the GitHub action.
+
+```yaml
+# This workflow builds a list of your starred repositories
+name: Stargazer
+
+on:
+  schedule:
+    - cron: '42 2 * * *'
+
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v2
+
+      # Generate the list
+      - name: Create star list
+        id: stargazer
+        uses: rverst/stargazer@5e231084ea229d6649fcaeaa04c4f3e336b57139
+        with:
+          github-user: ${{ github.actor }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          list-file: "README.md"
+          # you can ignore repositories, that will not get on the list
+          # ignored-repositories: ${{ secrets.IGNORE_REPO }}
+
+      # Commit the changes
+      - name: Commit files
+        run: |
+          git config --local user.email "[email protected]"
+          git config --local user.name "github-actions[bot]"
+          git add .
+          git commit -m "Update list"
+
+      # Push the changes
+      - name: Push
+        uses: ad-m/github-push-action@master
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          branch: ${{ github.ref }}
+```
+
+## Inputs
+
+| Name | Type | Required | Description |
+|------|------|----------|---------|-------------|
+| github-user | string | true GitHub user whose stars are fetched |
+| github-token | string | true Access token for the GitHub API |
+| list-file | string | false Filename of the stargazer list (default: README.md) |
+| ignored-repositories | string | false | Comma separated list of repositories (user/repo) to ignore |
+
 ## Inspiration
 
 *stargazer* is inspired by [starred](https://github.com/gmolveau/starred),
 which is very similar and written in python. I created *stargazer* because I
-wanted to try out the [GitHub GraphQL API v4](https://docs.github.com/en/graphql). 
+wanted to try out the [GitHub GraphQL API v4](https://docs.github.com/en/graphql).